1. Field of the Invention
This invention relates to X-ray diagnostic apparatuses and, more particularly, to an X-ray diagnostic apparatus provided with safety means which senses physical contact between component devices, such as an X-ray exposure unit and an image intensifier, and peripheral objects located in surrounding areas and which stops the operation of the X-ray diagnostic apparatus upon occurrence of such contact.
2. Description of the Related Art
An X-ray diagnostic apparatus of the type mentioned for use in medical diagnosis is known wherein a rotation arm of substantially a letter C-shaped configuration having a pair of confronting arm units is mounted on a rotating support secured to a wall or ceiling, and component members typically including an X-ray exposure unit, an image intensifier, etc. are respectively disposed on free ends of the arm units. Adjacent the arm support side of the X-ray diagnostic apparatus is placed a catheter table having thereon a lengthwisely slidable top plate on which a subject to be examined or diagnosed is placed. The rotation arm is rotatable in a horizontal direction with the rotation of the rotating support and is rotatable also about its own axis at a point at which it is mounted to the rotating support. Further, the rotatable support is vertically movable to provide for position adjustment. In the X-ray diagnostic apparatus so constructed, an X-ray diagnostic operation may take place by rotating the rotation arm in relation to the rotation of the rotating support or rotating the same about its own axis, thereby to permit the above component devices to move to a desired location around the subject lying on the top plate of the catheter.
In operating the X-ray diagnostic apparatus, it frequently occurs that the component devices, as they rotate or travel, come into contact with peripheral objects including, for example, a top plate of the catheter table, its support stand, monitoring equipment, as well as moving objects including a subject and an operator, that lie in the path of the movable component members.
Safety measurements taken in a conventional device of the type mentioned provide for contact switches in the path of moving component members, the sensor switches being operative upon occurrence of contact between them and an peripheral or neighboring object to stop or fault the operation of the rotation arm, thus attaining safety in operation and avoiding damages arising out of the contact.
The known contact switch is constructed by a tape switch attached to the rear surface of a resin or metallic cover mounted, via spring means, on a component member, such as, the forward surface of an image intensifier, and a dogg projecting from the same surface at a side opposite the tape switch, in such a manner that the tape switch and the dogg are held in connection or disconnection by external forces applied to the cover. This arrangement, however, involves the following drawbacks.
1. The drive of the switch is by a spring force, so that it is difficult to make adjustment and the operation of the switch is not stable.
2. The operation of the switch is limited regarding a direction in which forces are applied. The switch is less effective against forces that are applied in directions other than a direction in which the switch and the dogg face each other.
3. The construction of the cover having the switch is complicated and does not provide a good touch in the event a subject contacts the cover.